A simulation facility for stochastic micropopulation models at the University of Minnesota utilizes a VAZ 11/750 and VMS to run a locally-developed software system called SUMMERS (Simulation Utilities and Monte Carlo Methods for Epidemiological Research Studies). Since SUMMERS is highly modularized, it can be adapted to the simulation of different populations and models of different diseases by changing a limited number of program modules and variable subsets. Various program modules operate the user interfaces, the simulation process, the control functions, the report generation, and the analytic interpretation. Extensive software is being developed for sensitivity analyses of the multivariate parameters which are estimated stochastically. Hardware and software are assembled and integrated to enable convenient, research-oriented studies of stochastic population models. Current model development and research focuses on models of infectious disease epidemics, chronic cardiovascular disease, genetic ascertainment of diabetes, and data distributions from the clinical laboratory. The results of these simulations are of use in analyzing mechanisms of disease incidence, prevalence and case-finding, as well as in exploring strategies for prevention or limitation of spread. These studies and the outcomes of collaborative studies help test the applicability and friendliness of the facility offerings. It will also train new users, disseminate materials concerning the research and facilities available, and provide modeling services for remote users. During the first three years of renewal, different transfer modes will be developed for external users, ranging from multi-user, multi-function programming systems running on super micro- or mini-computers, to single user, single function systems dedicated to a particular version or model type, and to smaller microcomputer versions suitable for demonstration in the classroom or at seminars. Network facilities will also be investigated to link the community of SUMMERS users to other BRT simulation facilities and to each other.